EP0905788A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
MOS type image sensing device
Assignee: Canon Inc
•
Filing: 1998-09-28
•
Granted: —
•
Expires: 2018-09-28
Abstract
Abstract In a photoelectric conversion device having a plurality of pixel cells each of which includes a photoelectric conversion element (1), a field effect transistor (102) having the gate area for storing signal charge generated by the photoelectric conversion element and the source-drain path for outputting a signal corresponding to the signal charge stored in the gate, a first power supply line (4, 5) for supplying electric power to the field effect transistor, and a first switch (103) connected between the field effect transistor and the first power supply line, when a reset voltage for resetting the gate of the field effect transistor is V sig0 , a threshold voltage of the field effect transistor is V th , current flowing through the field effect transistor is I a , a voltage applied via the first power supply line is V c1 , and a series resistance of the first switch is R on , each pixel cell is configured to satisfy a condition determined by V c1 - R on × I a > V sig0 - V th .
Inventors
- 👤 Tetsunobu Kochi
- 👤 Isamu Ueno
- 👤 Toru Koizumi
- 👤 Hiroki Hiyama
- 👤 Shigetoshi Sugawa
- 👤 Katsuhisa Ogawa
- 👤 Katsuhito Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:31
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H04; H04N; H04N25/00; H04N25/70; H04N25/76; H04N25/77; H04N25/771; H04N25/50; H04N25/57; H04N25/59; H04N25/60; H04N25/65; H04N25/67; H04N25/671; H04N25/766; H04N25/78; H10F39/011; H10F39/014; H10F39/80; H10F39/803
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
182 words
A photoelectric conversion device having a
plurality of pixel cells each of which includes a
photoelectric conversion element (1), a field effect
transistor (102) having the gate area for storing signal
charge generated by said photoelectric conversion
element and the source-drain path for outputting a
signal corresponding to the signal charge stored in the
gate, a first power supply line (4, 5) for supplying
electric power to said field effect transistor, and a
first switch (103) connected between said field effect
transistor and said first power supply line, said device
is characterized in that, when a reset voltage for resetting the gate of said
field effect transistor is V sig0 , a threshold voltage of
said field effect transistor is V th , current flowing
through said field effect transistor is I a , a voltage
applied via said first power supply line is V c1 , and a
series resistance of said first switch is R on , each pixel
cell satisfies a condition determined by V c1 - R on × I a > V sig0 - V th .
Claim 2
Dependent Claim
51 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102), and said
first switch (103) and said second switch are field
effect transistors having different threshold voltages
from each other.
Claim 3
Dependent Claim
46 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are made to have different threshold
voltages by making channel regions (401, 404) of said
first switch and said second switch have different
impurity concentrations from each other.
Claim 4
Dependent Claim
46 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are made to have different threshold
voltages by making well regions (401, 501) of said first
switch and said second switch have different impurity
concentrations from each other.
Claim 5
Dependent Claim
46 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are made to have different threshold
voltages by making gate dielectric films (601, 602) of
said first switch and said second switch have different
thickness from each other.
Claim 6
Dependent Claim
48 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are made to have different threshold
voltages by making gate dielectric films of said first
switch and said second switch with different materials
having different dielectric constants from each other.
Claim 7
Dependent Claim
55 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are formed on different well regions
(501) which are isolated from each other, and said first
switch and said second switch are made to have different
threshold voltages by applying different voltages to
said respective well regions.
Claim 8
Dependent Claim
56 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are insulated-gate field effect
transistors, and said first switch and said second
switch are made to have different threshold voltages by
making said first switch and said second switch have
different gate lengths (801, 802) from each other.
Claim 9
Dependent Claim
56 words
The photoelectric conversion device according
to claim 2, wherein said first switch (103) and said
second switch (114) are insulated-gate field effect
transistors, and said first switch and said second
switch are made to have different threshold voltages by
making said first switch and said second switch have
different gate widths (803, 804) from each other.
Claim 10
Dependent Claim
60 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102), said first
switch (103) and said second switch are field effect
transistors, and different voltages (V2, V3) are applied
to gates of said first switch and said second switch.
Claim 11
Dependent Claim
81 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102) and a second
power supply line (1001) for supplying electric power of
a voltage (V c2 ), different from the voltage (V c1 ) applied
via said first power supply line (4), to said second
switch (114), and said first switch (103) and said
second switch are field effect transistors.
Claim 12
Dependent Claim
63 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102) and a
capacitor (1101) formed between said second switch and
the gate area of said field effect transistor, and the
gate voltage of said field effect transistor is
controlled via said capacitor.
Claim 13
Dependent Claim
80 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102) and a third
switch (1201) connected between said photoelectric
conversion element (1) and an intersection of said
second switch and the gate area of said field effect
transistor, and capacitance of the gate area of said
field effect transistor is set lower than capacitance of
said photoelectric conversion element.
Claim 14
Dependent Claim
149 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102), and said
first switch (103) and said second switch are field
effect transistors, and, when mobility is µ, capacitance
of gate oxide per unit area is Cox, gate width is W, and
gate length is L in said first switch, and K = 1/2 × µ
× Cox × W/L, a threshold voltage of said second switch
is V th0 , a threshold voltage of said first switch is V th1 ,
the gate voltage of said second switch is V2, and the
gate voltage of said first switch is V3, then, each
pixel cell satisfies a condition determined by V3 - V th1 - (I a /K) 1/2 > V2 - V th0 - V th .
Claim 15
Dependent Claim
65 words
The photoelectric conversion device according
to claim 14, wherein the gate voltage V2 of said second
switch (114) and the gate voltage V3 of said first
switch (103) are controlled equal, and the threshold
voltage V th of said field effect transistor (102), the
threshold voltage V th0 of said second switch and the
threshold voltage V th1 of said first switch are set equal.
Claim 16
Dependent Claim
57 words
The photoelectric conversion device according
to claim 14, wherein the gate voltage V2 of said second
switch (114) and the gate voltage V3 of said first
switch (103) are controlled equal, and the threshold
voltage V th0 of said second switch is set different from
the threshold voltage V th1 of said first switch are set
equal.
Claim 17
Dependent Claim
59 words
The photoelectric conversion device according
to claim 14, wherein the gate voltage V2 of said second
switch (114) is controlled to be different from the gate
voltage V3 of said first switch (103), and the threshold
voltage V th0 of said second switch is set different from
the threshold voltage V th1 of said first switch are set
equal.
Claim 18
Dependent Claim
160 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102), and said
first switch (103) and said second switch are field
effect transistors, and, when mobility is µ, capacitance
of gate oxide per unit area is Cox, gate width is W, and
gate length is L in said first switch, and K = 1/2 × µ
× Cox × W/L, a threshold voltage of said second switch
is V th0 , a threshold voltage of said first switch is V th1 ,
the gate voltage of said second switch is V2, and the
gate voltage of said first switch is V3, then, each
pixel cell satisfies a condition determined by V3 - V th1 - (I a /K + (V3 - V c1 - V th1 ) 2 ) 1/2 > V2 - V th0 - V th .
Claim 19
Dependent Claim
197 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102) and a second
power supply line (1001) for supplying electric power of
a voltage, different from the voltage (V c1 ) applied via
said first power supply line (4), and said first switch
(103) and said second switch are field effect
transistors, and, when mobility is µ, capacitance of
gate oxide per unit area is Cox, gate width is W, and
gate length is L in said first switch, and K = 1/2 × µ
× Cox × W/L, a threshold voltage of said second switch
is V th0 , a threshold voltage of said first switch is V th1 ,
the gate voltage of said second switch is V2, the gate
voltage of said first switch is V3, and the voltage
applied via said second power supply line is V c2 , then,
each pixel cell satisfies a condition determined by V3 - V th1 - (I a /K) 1/2 > V c2 - V th where V c2 ≤ V2 - V th0 .
Claim 20
Dependent Claim
208 words
The photoelectric conversion device according
to claim 1, wherein each of said pixel cells further
comprises a second switch (114) for resetting said gate
area of said field effect transistor (102) and a second
power supply line (1001) for supplying electric power of
a voltage, different from the voltage (V c1 ) applied via
said first power supply line (4), and said first switch
(103) and said second switch are field effect
transistors, and, when mobility is µ, capacitance of
gate oxide per unit area is Cox, gate width is W, and
gate length is L in said first switch, and K = 1/2 × µ
× Cox × W/L, a threshold voltage of said second switch
is V th0 , a threshold voltage of said first switch is V th1 ,
the gate voltage of said second switch is V2, the gate
voltage of said first switch is V3, and the voltage
applied via said second power supply line is V c2 , then,
each pixel cell satisfies a condition determined by V3 - V th1 - (I a /K + (V3 - V c1 - V th1 ) 2 ) 1/2 > V c2 - V th where V c2 ≤ V2 - V th0 .
Claim 21
Dependent Claim
101 words
A photoelectric conversion device having a
plurality of pixel cells each of which includes a
photoelectric conversion element (901), a first switch
(911) for transferring charge generated by said
photoelectric conversion element, a field effect
transistor (903), having the gate area for receiving the
transferred charge, for outputting a signal
corresponding to the charge stored in the gate area, and
a second switch (902) for resetting the gate area of
said field effect transistor, said device is
characterized in that, threshold voltages of said first switch and said
second are made different from a threshold voltage of
said field effect transistor.
Claim 22
Dependent Claim
34 words
The photoelectric conversion device according
to claim 21, wherein the threshold voltage of said field
effect transistor (903) is greater than the threshold
voltages of said first switch (911) and said second
switch (902).
Claim 23
Dependent Claim
40 words
The photoelectric conversion device according
to claim 21, wherein each of said pixel cells further
includes a third switch (904) connected between said
field effect transistor (903) and a power supply for
providing electric power to said field effect transistor.
Claim 24
Dependent Claim
29 words
The photoelectric conversion device according
to claim 21, wherein said second switch (902) and said
third switch (904) are field effect transistors having
different threshold voltages from each other.
Claim 25
Dependent Claim
84 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold voltage of said
field effect transistor (903) for outputting signals is
made different from the threshold voltages of said first
switch and said second switch by making an impurity
concentration in channel region of said field effect
transistor be different from impurity concentrations in
channel regions of said first switch and said second
switch.
Claim 26
Dependent Claim
84 words
The photoelectric conversion device according
to claim 25, wherein the threshold voltage of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch (911) and said second switch (902) by doping all
the channel regions of said field effect transistor for
outputting a signal, said first switch, and said second
switch with dopant of a predetermined impurity
concentration, first, then further doping a channel
region of said field effect transistor for outputting a
signal.
Claim 27
Dependent Claim
84 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch and said second switch by making well region of
said field effect transistor for outputting a signal
have an impurity concentration different from well
regions of said first switch and said second switch.
Claim 28
Dependent Claim
88 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch and said second switch by making the gate
dielectric film of said field effect transistor for
outputting a signal have a thickness different from
thickness of gate dielectric films of said first switch
and said second switch.
Claim 29
Dependent Claim
91 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch and said second switch by making the gate
dielectric film of said field effect transistor for
outputting a signal with material having dielectric
constant different from dielectric constants of gate
dielectric films of said first switch and said second
switch.
Claim 30
Dependent Claim
112 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and said field effect transistor
(903) for outputting a signal, said first switch and
said second switch are formed on different well regions
which are isolated from each other, and the threshold of
said field effect transistor for outputting a signal is
made different from the threshold voltages of said first
switch and said second switch by applying a voltage,
different from a voltage applied to the well regions of
said first switch and second switch, to said field
effect transistor for outputting a signal.
Claim 31
Dependent Claim
80 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch and said second switch by making said field
effect transistor for outputting a signal have gate
length different from gate length of said first switch
and said second switch.
Claim 32
Dependent Claim
80 words
The photoelectric conversion device according
to any one of claims 21 through 24, wherein said first
switch (911) and said second switch (902) are field
effect transistors, and the threshold of said field
effect transistor (903) for outputting a signal is made
different from the threshold voltages of said first
switch and said second switch by making said field
effect transistor for outputting a signal have gate
width different from gate width of said first switch and
said second switch.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.